Escaping gas alarm



Oct. 3, 1939. J CALDWELL 2,174,820

ESCAPING GAS ALARM Filed Dec. 29, 1937 Jbhn P CaZcZweZZ W42 w. W

Patented Oct. 3, 1939 UNITED STATES PATENT OFFICE E SCAPING GAS ALARM 2Claims.

My invention has for an object the prevention of asphyxiation byescaping gas from gas jets and other places within a room.

A further object is to provide an apparatus for 6 setting into action anaudible alarm and visual signals located at suitable places to givewarning of the escaping gas and to enable prompt rescue Work to be doneif and when necessary.

Further, it is an object to provide a simple, inexpensive apparatusinfluenced by the escaping gas to close an electric signaling circuit bymeans of which warning is given at one or more places of impendingdanger.

Again, it is an object to provide an apparatus which will not only givean alarm when gas is escaping into a room from a light fixture, a stoveor heater, etc., but which will also break a window to the room so as tolet in fresh air and thereby so dilute the escaping gas that theatmosphere in the room will no longer be asphyxiating.

Other objects will in part be obvious and in part be pointed outhereinafter.

To the attainment of the aforesaid objects and ends the invention stillfurther resides in the novel details of construction, combination andarrangement of parts, all of which will be first fully described in thefollowing detailed description and then be particularly pointed out inthe appended claims, reference being had to the accompanying drawing, inwhich:

Fig. 1 is a view, partly diagrammatic and partly in vertical section, ofone embodiment of my invention.

Fig. 2 is an enlarged detail section of a portion of the controlapparatus.

Fig. 3 is an enlarged detail section on the line 3-3 of Fig. 1.

In the drawing, in which like numerals and letters of reference indicatelike parts in all the figures, I is a suitable base on which is mounted,in any suitable way, the actuating apparatus of my invention. Thisapparatus comprises a Davy type lamp having a fount 2 for fuel oil and aburner 34 which is screwed into, or otherwise detachably held in, thebase 5 of the chimney.

The chimney comprises a suitable frame composed of the base 5, verticalbars 6 and horizontal ring 1 covered with a fine mesh screen wirecylinder 8.

The ring I is preferably threaded to receive the threaded base ring Inof the cap 9 which is also composed of fine mesh wire screen.

A plate II is soldered, or otherwise secured tightly, to the screen 8and to a similar screen cylinder l2 and serves to unite the cylinders 8and 12 into an integral structure.

The screens 8 and i2 and plate H have aligning holes through whichpasses one end of a curved guide I6, a collar ll being preferablyprovided on the guide IE to prevent the guide being drawn into cylinder3 should the guide become loose. The guide is soldered to the screens 8and i2 and to the plate I I to hold it in position.

l3 and I4 designate the frame and I5 represents the base for thecylinder l2.

Within the cylinder 12 is suspended a weight 20 on a flexible(preferably metal) cable that passes through the guide l6 into thecylinder 8 where it is provided with a stop l8 and a hook l9, therebeing a second hook 25 carried on a member 24 that is rigidly soldered,or otherwise secured, to the cylinder opposite the guide IS. The mem ber24 may be made of poor heat-conducting material if desired, although itsprincipal purpose is to prevent burning cord from getting too close tothe screen wall 8.

Joining the hooks 25 and Hi, to hold up the weight 20, is a loop orpiece of fusible material 26. This material may be cord, either plain orasbestos covered, or it may be of any suitable material which will burnor fuse at a predetermined time, as when the flame from burner 34reaches it, but which will not burn or fuse under normal condition ofthe flame.

Projecting into cylinder i2 is an electric switch 22, preferably of thesnap type, whose lever 23 is positioned to be moved from the offposition to the on position by the weight 20 when released by burning orfusing of the member 26.

The switch 22 may be used to control one or more electric circuits togive warning, or to operate other desired instrumentalities if and whengas escapes into a room. For purposes of illustration only, and not forpurposes of limitation, I have shown in Fig. 1 an electric circuit 21connected to switch 22 and including a source of energy 28, signallights W and R and an audible signal (bell or gong) B. I have also shownone way in which the closing of switch 22 may be utilized to break awindow to let in fresh air.

In the embodiment illustrated, 29 designates a window, 30 an inclinedchute, 3| a projectile which will, when released, be moved by gravitydown the chute and crash into the window pane, thus breaking the sameand letting in fresh air. The projectile may be of any desired kind andany suitable means may be used to keep it static when the condition ofthe room is normal. The projectile-retaining means may comprise a stoppin 33 that projects into the path of the projectile SI and that isreleasable by a magnet 32 (connected in the circuit El) which isenergized while switch 22 is in the on position.

I have observed that when combustible gas enters the cylinder 8 whilethe lamp is burning, the flame will flare up, so I have taken advantageof this phenomenon. Normally the flame is too low to fuse or burn member23, but when it flares up in the presence of gas, it will cause 23 toignite or fuse and release the weight to throw the switch on.

The switch 22 may be slidably mounted on base I so it can be withdrawnfrom cylinder l2 when it is necessary to re-set the switch, r there-setting may be accomplished in other ways if desired. To preventswinging of the weight against the screen 62, as well as to guide theweight in falling, a rigid tube 25 may be provided in which the weightoperates and through a slot in the side of which the l ver 23 of theswitch projects.

In the drawing I have shown the Davy type lamp as provided with but onescreen El; obviously two or more screen walls may be employed, as founddesirable.

While I have shown a preferred embodiment of the invention, modificationthereof and changes in the details of construction can be made withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

When in the claims I refer to fusible means, I wish that term to beunderstood as including means which will separate or sever by burning,as well a means which liquefles under heat and thus effects separation.

What I claim is:

1. In apparatus of the class described, means for effecting the actionof a switch which closes an electric circuit, said means comprising alamp having a burner and a wire screen cylinder in which the flame ofthe lamp is located, a second screen cylinder adjacent the firstmentioned screen cylinder, a guide member projected into each screencylinder, a flexible wire or cable passing from one cylinder to theother through said guide, fusible means in the first cylinder forholding said cable against movement, and a weight suspended by saidcable in said second cylinder and releasable by the fusing of saidfusible means to fall and thereby to actuate said switch to its onposition, said fusible means being so positioned over the lamp burnerthat when the flame flares up it will cause said fusible means to severand release the cable.

2. In apparatus of the class described, means for effecting the actionof a switch which closes an electric circuit, said means comprising alamp having a burner and a wire screen cylinder in which the flame ofthe lamp is located, a second screen cylinder adjacent the firstmentioned screen cylinder, a guide member projected into each screencylinder, a flexible wire or cable passing from one cylinder to theother through said guide, fusible means in the first cylinder forholding said cable against movement, and a weight suspended by saidcable in said second cylinder and releasable by the fusing of saidfusible means to fall and thereby to actuate said switch to its onposition, said fusible means being so positioned over the lamp burnerthat when the flame flares up it will cause said fusible means to severand release the cable, said lamp having a removable top to its cylinderto allow access to the cylinders interior for the purpose of renewingthe fusible member and resetting the weight.

JOHN P. CALDWELL.

